<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="utf-8"/>
    <title></title>
</head>
<body>
<script type="text/javascript">
    Number.prototype.aa = function() {
        alert("aa");
    };
    Object.prototype.bb = function() {
        alert("bb");
    };
    var a = 2;
    var c = new String("dfd");
    c.dd = function() {
        alert("dd");
    };
    a.aa();
    a.bb();
    c.bb();
    c.dd();

</script>
</body>
</html>